From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8DB7C4332B for ; Mon, 11 Jan 2021 14:25:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C64C22515 for ; Mon, 11 Jan 2021 14:25:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388518AbhAKOYk (ORCPT ); Mon, 11 Jan 2021 09:24:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731452AbhAKOYj (ORCPT ); Mon, 11 Jan 2021 09:24:39 -0500 Received: from mail-lf1-x134.google.com (mail-lf1-x134.google.com [IPv6:2a00:1450:4864:20::134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2709DC061786 for ; Mon, 11 Jan 2021 06:23:59 -0800 (PST) Received: by mail-lf1-x134.google.com with SMTP id u25so17201388lfc.2 for ; Mon, 11 Jan 2021 06:23:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=AUnHjmoZBMPPrCWzaTempqIXz+G+HPhuggI2H5BxADg=; b=NYTw7WWk1Zf7aSea06TGNnxIUYEc7qq9AW/lldbVIlJWFwcFfjUZfoog7LIDmbomQT 4Ji/pCiUBy/Pvci3hJLsfml51b/4OYHgCYH4usuGLc9BYLPBS8Y+4CYEzlI+KLerC4mo euxtuBpAYikzhBtptV3Xzt0M8bEon0shmqoSYFufDnj8HNvqVXDrVTpmig6MMDU8p2jx 25RftUJXI7+SCtdFIWtP4yxlAtQoYFXLf8D+XQUUs5oU1AuI7YWugV2r114YA9HR46kM cf7/Xcv8oKNI1EpyOw6GOwJwUXCAvwi6v0reLfn4RacXEr4OCuBK5zxbX6JYIJSbxoza +lFw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=AUnHjmoZBMPPrCWzaTempqIXz+G+HPhuggI2H5BxADg=; b=rpSF4ml4W6NN5D012iSVWQVQ9ym+CfytS/LbFQsKfSxbvimKx01P+sJRTXtXSNIC/R z6N0ybxlaUNU715/5U37CLXJuBObGDWCwf08IxDFFDRfYbEGWkAqH8hiqgHIuKgd16zG l5ywJnrUXLx5ZE2HqPevrXcROFsdNEY8MpcMzAq8kmVqCLXnF3SBeCDkWCj8fSIyaXGh webPk9AsjVNjDtWICSo5CSgXUiEMDjJ7tEyEjBjogsmG2n27c3/Ol1/qazs5NY9AX/Gx R+N32ZorX9xCJGpT62qpIfXK6bI6NCTqI0sf4SDraDSTHfcusoevFqpNvrdZ6PcUzQN3 d80w== X-Gm-Message-State: AOAM532gjZJlVKk+6X5SqkFHaTkD8SklEUP/3uP8iozERTEVTialxHkb ptciZAWgbamp9F/EPDUz45RB3w== X-Google-Smtp-Source: ABdhPJymqRDS7aCC5+LCmHPbk12XaMGmyO8JI869mpSwvL1L+s3a8s0ee2CPCpojY5XXzdU39KLClA== X-Received: by 2002:a05:6512:2f7:: with SMTP id m23mr6896463lfq.517.1610375037710; Mon, 11 Jan 2021 06:23:57 -0800 (PST) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id w23sm2310181lff.84.2021.01.11.06.23.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Jan 2021 06:23:57 -0800 (PST) Received: by box.localdomain (Postfix, from userid 1000) id 3623C102238; Mon, 11 Jan 2021 17:24:02 +0300 (+03) Date: Mon, 11 Jan 2021 17:24:02 +0300 From: "Kirill A. Shutemov" To: Linus Torvalds Cc: Will Deacon , Linux Kernel Mailing List , Linux-MM , Linux ARM , Catalin Marinas , Jan Kara , Minchan Kim , Andrew Morton , "Kirill A . Shutemov" , Vinayak Menon , Hugh Dickins , Android Kernel Team Subject: Re: [PATCH v2 0/3] Create 'old' ptes for faultaround mappings on arm64 with hardware access flag Message-ID: <20210111142402.6euyktmcnpemanf7@box> References: <20210108171517.5290-1-will@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 08, 2021 at 11:34:08AM -0800, Linus Torvalds wrote: > I still dislike how we basically randomly modify the information in > that 'vmf' thing. I wounder if it would be acceptable to pass down to faultaround a copy of vmf, so it mess with it without risking to corrupt the original one? We would need to transfer back prealloc_pte, but the rest can be safely discarded, I believe. But it's somewhat wasteful of stack. sizeof(vmf) == 96 on x86-64. -- Kirill A. Shutemov